My recommendation would be the Hastings high-rib trap barrel that is sold by Shotgun Sports Magazine (URL above). The barrel is the old standard external diameter, is overbored to .740" and comes with a longer forcing cone and nice long choke tubes. Mine patterns very well and they look a lot nicer than the Remington barrel in the finish department. Like any standard-size barrel, it will require you to open up the wood on your forend a little for clearance.

The rib is not "high" like the current wave of high-ribbed guns. It is about twice as high as the Remington rib and tapers slightly in both height and width toward the muzzle. For some reason, there are no photos of the barrel on SSM's website but if you send me an email, I can send you a photo of the two barrels with the ribs against one another for comparison.

The Hasting barrel is a much higher quality barrel than a new Remington barrel. I hate too say that but it is true even if the barrel is French made. The price is high also because of the dollar vs euro. I would try to buy an older step rib trap barrel they were great barrels just make sure the locking lug inside the barrel where the bolt locks up is in good shape. You can always get it welded up but I prefer a good original trap barrel.
Buddy